1. Technical Field
The present invention relates to a recording apparatus for recording onto a recording medium.
Recording apparatuses include inkjet printers, copiers, facsimiles, and other such apparatuses.
2. Related Art
A configuration in which a mobile element of the apparatus, e.g., a paper discharge tray, an operation panel, or the like is made to operate automatically via a driving force of a motor is in some instances employed in a printer in order to improve the ease of use for the user.
For example, Japanese laid-open patent publication No. 2000-327203 discloses a configuration in which a paper discharge tray for stacking a sheet material is either stowed inside an apparatus main body or exposed from the apparatus main body by a driving means.
A configuration disclosed in Japanese laid-open patent publication No. 2000-327203, where a paper discharge tray is moved in and out by the power of a motor shall here be taken as an example to describe a problem thereof. First, when the paper discharge tray is being automatically moved out from the apparatus main body, if there is an obstacle in a region of protrusion of the paper discharge tray, then there is the risk that the paper discharge tray could collide with the obstacle, consequently causing damage to the paper discharge tray or to the drive mechanism thereof. There is additionally the risk that over-rotation of the motor could cause the drive mechanism to break. This results in the need to employ a configuration where a clutch with which a friction disk is used (called a “friction clutch” below) is provided to a power transmission pathway between the motor and the paper discharge tray, to cause slipping (idling) to be produced in the friction clutch when at least a predetermined torque is produced in the power transmission path.
Users also have demands, however, such as wishing to be able to operate the paper discharge tray (move the paper discharge tray in and out) not by the power of the motor but rather directly by hand. In such a case, a rotational shaft of the motor is turned by moving the paper discharge tray, and cogging of the motor at this time may in some instances cause an unpleasant feeling or noise for the user.
As such, in order to avoid such problems, preferably, slipping (idling) is produced with the friction clutch before the motor is turned in association with cogging when the paper discharge tray is operated directly by hand, and then the slipping (idling) continues with the friction clutch. That is to say, preferably, the friction clutch has a smaller slipping start torque than the cogging torque.
Because the friction clutch makes use of a force of friction, there exist the two concepts of the torque of when slipping is produced when torque is applied to the friction clutch (this being torque caused by static frictional force) and the torque during the time when the slipping is taking place (this being torque caused by kinetic frictional force), but the phrase “slipping start torque” in the present specification signifies the former, i.e., the torque caused by static frictional force.
Then, if the slipping start torque of the friction clutch ends up being reduced due to the reasons described above, slipping may in some instances end up taking place in the friction clutch when an attempt is made to move the paper discharge tray in or out by the driving force of the motor, i.e., it may in some instances be impossible to drive the paper discharge tray normally.